Installation for cultivation of plants on a conveyor belt

ABSTRACT

The invention relates to a method for the cultivation of plants, comprising the following steps: 
     a) placing root containers (2) containing a plant on a cultivation conveyor belt (4), 
     b) allowing the plants (3) cultivated in the root containers to grow on said cultivation conveyor belt whilst the cultivation conveyor belt is stationary, 
     c) using the cultivation conveyor belt to transport the root containers placed on the cultivation conveyor belt to a dispensing point (14), for example when the plants have grown sufficiently or have to be given an intermediate treatment. 
     With this method it is advantageous if the cultivation conveyor belt (4) extends through a tray (1) having raised side walls (5) so that water can be supplied to the tray during step b) without said water flowing away of its own accord. The invention also relates to an installation for application of the method.

This application is a division of application Ser. No. 08/392,343, filedFeb. 22, 1995, now U.S. Pat. No. 5,561,943.

The present invention relates to a method for the cultivation of plants,in particular for the cultivation of plants in greenhouses.

The cultivation of plants in greenhouses is generally known. With thisprocedure the plants are frequently grown in root containers, such aspots filled with compost, substrate, etc. With this known procedure, theroot containers containing plants are placed alongside one another onthe nursery floor in a greenhouse. When the plants have grownsufficiently, the root containers containing plants are lifted one byone, or in grouped units, by hand or with the aid of manually operateddevices and placed on a trolley for removal. The plants can then besubjected to a more detailed selection, for example on the basis ofcolour, and dispatched, for example to an auction.

Said removal of the cultivated plants from the nursery floor by hand ishighly labour-intensive. Moreover, the nursery floors concerned oftencover a very large area and staff therefore have to walk back and fortha fairly appreciable number of times.

Over the years attempts have been made to automate cultivation processesof this type. Thus, for example, a system is known with which the rootcontainers containing plants are placed on large sheets and said sheetscan be moved with the aid of a roller conveyor. When the plants arefully grown the sheets are then moved one by one to the side of theroller conveyor and are then placed on a trolley for removal. Thissolution also is still fairly labour-intensive and, moreover, rollerconveyors and transport systems of this type are very expensive.

U.S. Pat. No. 4,166,341 discloses a complex method and apparatus for thecultivation of plants. The apparatus comprises a plurality of U-shapedchannels extending parallel. The channels are open at the outer ends andeach channel comprises a slidable supporting member extending throughthe gutter and supported at a distance above the bottom thereof byguides. The supporting member can be used for bringing plant beds in orout the channel. As the supporting member forms a liquid reservoir andcarries plant beds, stiffening of the supporting member in thetransverse direction of the channel is required, which makes thesupporting member relatively complex and expensive. Further thesupporting member is susceptible for leaving the tracks formed by theguides. Between the different growth stages the plant beds with plantsare transferred from one channel to another channel or the transversedistance between neighbouring channels is enlarged. How the tranfer ofbeds with plants between the channels is accomplished is not clear, itseems to be done manually. As said, the apparatus disclosed in U.S. Pat.No. 4,166,341 is complex and the method disclosed in U.S. Pat. No.4,166,341 labour-intensive.

EP-0,061,244 discloses a hollow trough having substantially closedsidewalls and a bottom. On a distance above the bottom extends anelongated flexible strip, which is slideably disposed in guides on thesidewalls of the trough. The strip contains a plurality of spacedapertures, in which plant pots are to be inserted. The underside ofplant pots inserted in the apertures of the strip lies at a distanceabove the bottom of the trough. The plant pots are manually placed intothe apertures by personel. The flexible strip is susceptible forbreakage as a result of the apertures, and further the flexible strip issusceptible for leaving the tracks formed by the guides on the sidewallsof the trough. How the plant pots can be discharged out of the trough isnot disclosed in EP-0,061,244, but this seems to be disclosed inEP-0,061,841 of the same applicant.

EP-A-0,061,841 discloses a complex device for discharging plant pots outof a trough like the trough disclosed in EP-A-0,061,244. The flexiblestrip is coupled to an elongating member, which pulls the flexible stripto wind it on a drum. The flexible strip is guided from the trough tothe drum along a descending slope, which slope ends at a cylinder, whichlifts the plant pots out of the apertures. The plant pots lifted out ofthe apertures in the flexible strip are placed on a working table forfurther manipulation. The coupling of the flexible strip to thedischarging device is not described but seems complex to accomplish inan automatic manner. If accomplished manually, the discharging deviceshould be accessible for personel. The discharge device according toEP-0,061,841 is unsuitable and unusable for placing plant pots in theapertures of the flexible strip extending in the trough.

The aim of the present invention is to automate the cultivation ofplants, in particular the removal of the cultivated plants from theplace of cultivation. In this context, a further aim of the invention isto provide a method which can be implemented using inexpensive means, sothat the cost per square metre is low.

This aim is achieved according to the invention by means of a method forthe cultivation of plants, comprising the following steps:

a) placing root containers containing a plant on a cultivation conveyorbelt,

b) allowing the plants cultivated in the root containers to grow on saidcultivation conveyor belt whilst the cultivation conveyor belt isstationary,

c) using the cultivation conveyor belt to transport the root containersplaced on the cultivation conveyor belt to a dispensing point, forexample when the plants have grown sufficiently or have to be given anintermediate treatment.

By installing a conveyor belt on the nursery floor and placing the rootcontainers containing plants thereon, the root containers containingplants can be removed automatically to a dispensing point, whenever thisis desired, by setting the conveyor belt in motion. This can, forexample, be the case when the plants have grown sufficiently. However,there are many other conceivable reasons why it can be desirabletemporarily to remove the root containers containing plants from theplace of cultivation, for example when the plants have to be inspectedfor, or treated for, diseases. Conveyor belts of this type can beproduced very inexpensively. Using relatively simple means, a web ofmaterial can be laid over, and also driven over, the nursery floor of agreenhouse in order to move the goods placed thereon off to one side.For example, it is conceivable as it were to cover the entire nurseryfloor with a single conveyor belt. However, it is also very readilyconceivable to install a multiplicity of strip-like conveyor belts overa single nursery floor and on each strip-like conveyor belt to place asingle row of root containers containing plants to be grown. Thecultivation conveyor belt according to the invention can comprise acontinuous conveyor belt, but can equally well be a conveyor beltextending between two winding drums, in which case the transportingeffect is obtained by winding the conveyor belt alternately between theone and the other winding drum.

According to the invention it is particularly advantageous when thecultivation conveyor belt extends with that section carrying the rootcontainers essentially in a tray delimited by raised walls, water,preferably a predetermined amount of water, being allowed to run intothe tray from time to time during step b). As a consequence of theraised walls of the tray, water is prevented from flowing away and theentire amount of water supplied to the tray can be taken up by the rootcontainers and plants. Wastage of water is thus completely prevented. Asis customary in the cultivation of plants, feed supplements andpesticides to prevent diseases are preferably added to said water. Thiswater containing feed supplements and pesticides constitutes anenvironmental pollutant and waste water therefore has to be treated.Because waste water can be completely avoided, there is therefore nopollution of the environment and it is even possible to dispense withtreatment installations. Water will be allowed to run into the tray fromtime to time, as required, but in practice it will be possible to dothis at set times, and often even periodically as the climate in agreenhouse can readily be adjusted and controlled.

In accordance with a further aim of the invention, if the dispensingpoint comprises a further conveyor belt, referred to as the mainconveyor belt, the method according to the invention can be furtherautomated by using the main conveyor belt during step a) to transportthe root containers containing plants to the cultivation conveyor beltand to transfer them to the latter. Numerous transfer mechanisms knownper se from the prior art, such as guides, can be used to effect saidtransfer. Thus, this further conveyor belt performs in this case adouble function.

According to an advantageous embodiment, in the method according to theinvention the cultivation conveyor belt is placed under tension onlybefore it is set in motion for transport purposes during step a) or stepc). This extends the life of a cultivation conveyor belt because thecultivation conveyor belt is under tension only when it has to fulfillits transporting role. A second advantage is that, in the case of acultivation conveyor belt lying within a tray, the root containerscontaining plants can easily be lifted over the edge of a tray after thecultivation conveyor belt has been placed under tension, whilst duringcultivation of the plants the weight of the root containers causes themto stand completely on the floor of the tray, so that they can readilytake up water.

According to the invention it is also advantageous if, during transportusing the cultivation conveyor belt, the root containers are fed betweenguide means extending on either side of, and parallel to, thecultivation conveyor belt. This prevents root containers being able tofall off the conveyor belt during transport, so that it is guaranteedthat all root containers containing plants can be removed from thenursery floor.

The method according to the invention can, in particular, be employedvery advantageously if the tray is a gutter and if the guide meanscomprise the longitudinal walls of the gutter. By using a multiplicityof gutters, each having one conveyor belt located therein, and placing asingle row of root containers on said conveyor belt, very goodadjustment and control of the water balance during the cultivationprocess can be achieved.

The invention also relates to an installation for application of themethod according to the invention.

The invention, specific embodiments and an illustrative embodiment willnow be explained in more detail with reference to a drawing.

Said drawing shows a perspective view of part of an installation forcarrying out the method according to the invention.

The FIGURE shows a gutter 1 which is to be installed on a nursery floorand in which the transport section of a cultivation conveyor belt 4 isinstalled. The gutter 1 is provided all round with raised walls 5, 6.The gutter 1 terminates at one end at a main conveyor belt 14, whichextends transversely to the longitudinal direction of the gutter.

As can be seen from the FIGURE the cultivation conveyor belt 4 is guidedby means of guides 12 and 16 in such a way that said belt 4 passesbeneath the main conveyor belt 14 and closely abuts the latter at guide12, so that goods can be transferred from the one conveyor belt to theother conveyor belt.

The cultivation conveyor belt 4 shown in the FIGURE is of the continuoustype and is tilted 90° between guide 16 and guide 11, so that thecultivation conveyor belt 4 has a vertical orientation. The cultivationconveyor belt 4 is then fed round guide 11 and guide 13, which islocated some distance away from the latter, and returned alongside thegutter to the other end of the gutter. The return section 17 of thecultivation conveyor belt 4 will have a vertical orientation to agreater or lesser degree depending on the pretensioning of thecultivation conveyor belt 4.

A drive unit, which has a drive motor, is indicated by 8, the drivemotor driving a toothed wheel 9. The toothed wheel 9 can be positionedbetween the guides 13 and 11 by means of a tilting movement in thedirection of arrow C, or a translational movement optionally incombination with a tilting movement, the cultivation conveyor belt 4being pretensioned by moving the entire drive unit 8 in the direction ofpressure roller 10. This will cause the cultivation conveyor belt 4 tobe clamped between drive wheel 9 and pressure roller 10, so thateffective driving of the cultivation conveyor belt 4 is possible.

As is also shown in the figure, root containers, such as pots 2, inwhich a plant 3 is growing can be placed on the cultivation conveyorbelt 4 in the gutter.

The cultivation process according to the invention is as follows:

Root containers 2 are supplied with the aid of the main conveyor belt14, which is movable in two directions as shown by arrow A. By means ofa guide, which extends over the main conveyor belt 14 and is not shown,the root containers 2 are guided onto the cultivation conveyor belt 4,which is movable in two directions as shown by arrow B. During thisoperation, the mutual spacing between root containers 2 guided onto thecultivation conveyor belt 4 can be adjusted as a function of the speedof the cultivation conveyor belt 4, the speed of the main conveyor belt14 and the spacing with which the root containers 2 have been placedapart on the main conveyor belt 14.

When the gutter 1 has been completely filled in this way with rootcontainers 2 placed sufficiently far apart, the cultivation conveyorbelt 4, and optionally also the main conveyor belt 14, are stopped. Thedrive unit 8 can then be disconnected from the cultivation conveyor belt4, the pretensioning on the cultivation conveyor belt 4 then also beingremoved, so that the cultivation conveyor belt 4 guided up over thefront end wall 6 of the gutter 1 comes into contact over its entirelength with the bottom of the gutter 1 under the weight of the rootcontainers 2.

A preferably predetermined amount of water can be fed into the gutter bymeans of a pipe 15 provided with discharge openings. A uniform supply ofwater over the entire gutter can be effected by means of a suitabledistribution of the discharge openings over the pipe 15.

When all of the water has been drawn up by the root containers and/orthe plant, a fresh amount of water can be supplied, if necessary. Itwill be clear that with this arrangement no water is wasted.

When the plant 3 has grown sufficiently, the cultivation conveyor belt 4can again be placed under tension and driven by means of the drive unit8. The drive will now be in the opposite direction. In this way the rootcontainers 2, containing the plant 3 which has grown sufficiently, areremoved onto the main conveyor belt 14, after which the furthertransport of the root containers 2 can be undertaken by the mainconveyor belt 14.

Since when the cultivation conveyor belt 4 is placed under tension itcomes a little away from the bottom of the gutter at the end of thegutter, it is advantageous according to the invention if additionalguides 7 are provided on either side of the end of the gutter. (Of theseguides, only the guide 7 on one side is shown.) For the remainder of thepath, the raised longitudinal side walls 5 act as a guide for the rootcontainers 2 during transport through the gutter 1. With thisarrangement the distance between the raised side walls 5 will be chosento be preferably somewhat larger than the diameter of the pots 2.

Numerous variants of the method and installation according to theinvention are conceivable, for example:

a brush can be fixed to the cultivation conveyor belt 4 so that duringtransport of the root containers 2 the gutter 1 is brushed clean at thesame time;

a multiplicity of gutters 1 positioned parallel to one another can beused, each with one cultivation conveyor belt 4, with which arrangementheating pipes can then be installed between adjacent gutters. Such aninstallation of heating pipes is advantageous and also does notadversely effect the light available for growing the plant;

the drive unit 8 can be movable on a rail along the main conveyor beltand can be used for alternately driving a multiplicity of cultivationconveyor belts 4;

the nursery floor can also comprise a large trough having a multiplicityof parallel cultivation conveyor belts therein, in which case raisedlongitudinal guides then have to be fitted between the cultivationconveyor belts to replace the longitudinal side walls 5 of the gutter;

the belt guides 16, 11, 13 can comprise rollers, but can also be smooth,stationary guide elements. The belt guides can also comprise a slotenclosing the conveyor belt so that the cultivation conveyor belt isheld in place.

I claim:
 1. Installation for the cultivation of plants growing in rootcontainers, comprising at least one tray having a base and raised wallsall round, at least one cultivation conveyor belt which at least partlyextends over the base of the tray, guide means, which are spacedsufficiently far apart for the root containers to fit between them,being fitted on either side along the conveyor belt, drive meansenabling the conveyor belt to transport to a dispensing point, and meansfor tensioning the conveyor belt during transportation of the rootcontainers and for relaxing the tension of the conveyor belt duringcultivation of the plants when the conveyor belt is stationary,furthercomprising feed means for water so that the water may be allowed to flowinto the tray from time to time, and wherein the tray is a gutter andwherein the guide means comprise the longitudinal side walls of thegutter, there being a multiplicity of said gutters arranged parallel toone another, each provided with one cultivation conveyor belt, one endof all gutters abutting a common main conveyor belt serving as adispensing point.
 2. Installation according to claim 1, furthercomprising a control unit which is movable on a rail along the mainconveyor belt and can be coupled to each respective cultivation conveyorbelt in order to drive the latter.
 3. Installation according to claim 2,wherein the control unit comprises tensioning means for placing therelevant cultivation conveyor belt under tension.
 4. Installation forthe cultivation of plants growing in root containers, comprising atleast one tray having a base and raised walls all round, at least onecultivation conveyor belt which at least partly extends over the base ofthe tray, guide means, which are spaced sufficiently far apart for theroot containers to fit between them, being fitted on either side alongthe conveyor belt, drive means enabling the conveyor belt to transportto a dispensing point, and means for tensioning the conveyor belt duringtransportation of the root containers and for relaxing the tension ofthe conveyor belt during cultivation of the plants when the conveyorbelt is stationary,wherein the cultivation conveyor belt is a continuousconveyor belt, the return section of which has an essentially verticalorientation.
 5. Installation for the cultivation of plants growing inroot containers, comprising at least one tray having a base and raisedwalls all round, at least one cultivation conveyor belt which at leastpartly extends over the base of the tray, guide means, which are spacedsufficiently far apart for the root containers to fit between them,being fitted on either side along the conveyor belt, drive meansenabling the conveyor belt to transport to a dispensing point, and meansfor tensioning the conveyor belt during transportation of the rootcontainers and for relaxing the tension of the conveyor belt duringcultivation of the plants when the conveyor belt is stationary,whereinsaid means for tensioning the conveyor belt during transportation of theroot containers and for relaxing the tension of the conveyor belt duringcultivation of the plants when the conveyor belt is stationary comprisemeans mounting the drive means for movement toward and away from thebelt.
 6. Installation according to claim 5, said drive means comprisinga motor that drives a drive wheel that contacts the belt and thatpresses the belt against a pressure roller when the drive means tensionsthe belt.